System of finishing plastic sheets



Oct. 4, 1949. 1. 1 .,LEsAvoY v 2,483,584

SYSTEM 0F FINI-SHING PLASTIC SHEETS Filed Aug. so, 1945 2 sneets-sheet 1 mvemos 1. LAWRENCE LEsAvoY. BY

ATTOQNEY.

Oct. 4, 1949. 1. L. I EsAvoY' SYSTEM 0F 'FINISHING PLASTIC SHEETS Filed Aug. 5o, 1945 2 Sheets-Sheet 2 INVENTOR I. LAwnN a LesAvoY. BY

ATTORNEY Patented Oct. 4, 1949 UNITED STATES PATENT OFFICE SYSTEM F FINISHIN G PLASTIC SHEETS I.Lawrence Lesavoy, Allentown, Pa. Application August 30, 1945, Serial No. 613,655

1 Claim. 1

This invention relates to apparatus for treating the surface of plastic sheets to give it a desired ornamentation or design. One object of the invention is to devise apparatus for giving the surface of plastic sheets a ribbed eiect; another object is to devise apparatus for giving the surface of plastic sheets a checkered effect. An important object of the invention is to devise apparatus for giving the surface of plastic sheets either a ribbed or a checkered eiect, depending upon adjustment of the apparatus. An allied object is to provide apparatus as described which may be readily adjusted to vary the surface ornamentation, whether ribbed or checkered. A further object of the invention is to devise apparatus for giving the surface of plastic sheets the designs of a selected pattern. An allied object is to provide apparatus as described in Which the design pattern may be readily changed.

For the attainment of these and such other objects as may appear or be pointed out, embodiments of the invention are shown in the accompanying drawing, wherein:

Referring to the drawings:

Figure 1 is a front View of the ratus;

Figure 2 is a sectional elevation taken on the line 2-2 of Figure l; i

Figure 3 is an end view of the gear transmission provided at the upper right end of machine as shown in Figure 2;

Figure 4 is a perspective view of the main drive transmissions and controls therefor;

Figure 5 is a perspective view of a portion of a plastic sheet having a ribbed surface according to the invention;

Figure 6 is a perspective view of a portion of a plastic sheet having a checkered surface according to the invention;

Figure '7 is a detail view of an arrangement for holding the rotary brushes against turning;

Figure 8 is a modified form of the invention shown in perspective employing compressed air and an apertured pattern plate; and

Figure 9 is a form similar to that of Figure 8, and also shown in perspective, but not employing a pattern plate.

Referring to Figures 1 and 2, the improved apparatus comprises an upper housing I El having a roof II, end walls I2, and side Walls I3, the bottom being open, and a lower housing having a iloor 2I, end walls 22 and side walls 23, being open at the top. As best seen in Figure 1, the end walls I2 of the upper housing I0 and the end walls 22 of the lower housing 2 are in vertical improved appaalignment and spaced to provide an elongated slot I4 at the left and a similar slot I5 at the right. As best seen in Figure 2, the side walls I3 of the upper housing Il) and the side walls 23 of the lower housing 20 are in vertical alignment and secured together, as by anges I3', 23'. An endless conveyor 30, provided for carrying plastic sheets A through the housing I0, 20, has an upper loop 3I passing through elongated slots I4, I5; the sheets are moved from left to right, as shown by the arrow, Figure 1. The belt 3| is supported by one or more bridge-pieces 25 spanning the lower housing 2i). Endless conveyor belt 3i) is looped between a, left pulley 33 and a right pulley 32, Figure 1.

Within the upper housing I0 are provided, as best seen in Figure 1, two rows of rotary brushes, the brushes of the left row being designated t0, and the right brushes, 50. The brushes (i6, 5), are secured on shafts, respectively, di', 5I, extending through the upper housing from side wall to side Wall, I3, as best seen in Figure 2; the ends of the shafts 4I, 5I outside of the housing are journaled in bearing members I6 (at the front, Figure 1, or

, to the left, Figure 2), 26 (at the right, Figure 2).

Shafts 5l, 4| are rotated to turn their respective brushes 5I), 40 in the same direction by the gear transmission best seen in Figure 3. To the right ends (as viewed in Figure 2) of shafts 5I, 4i are secured gears, respectively, 52, 42, Figure 3, which mesh with an idler gear 2 between 52 and 42. One of the gears, 42 as shown in Figure 3, also meshes with a pinion I on a short spindle 3, see Figure 2, which is coupled by a clutch 4 to a power shaft 6. Manual 5 of clutch 4 may be shifted to connect or disconnect the power drive of the rotary brushes 42, 52, as desired (for a purpose explained below).

The bearing members I6, 26, supporting the brush shafts 4I, 5I, are secured at the upper ends of vertical rods, respectively, Il, 21, mounted in bearings, conveniently provided in the housing flanges I3', 23', for an extent of vertical movement. At their lower ends, vertical rods II, 21 are provided with rollers, respectively I'B, 28 which are engaged by cams, respectively I9, 29. Cams I9, 29, are rotated (in a manner subsequently described) to raise the rotary brushes di), 5I) out of contact with the plastic sheets or lowered to engage the sheets (for a purpose which will soon be apparent).

The conveyor pulley 32, Figure 1, which may be rotated either continuously or intermittently, is secured on a shaft 34, on which is also secured a gear 35 (for continuous movement of the conveyor) and a disc 36 having spaced pin slots 31 (for intermittent movement of the conveyor). Gear 35 and pin-slot disc 36 are best "shown in Figure 4; gear 35 is driven by a gear 45 when the conveyor is required to be moved continuously, and dics 36 is driven by a crank arm 46 when the conveyor is required to :be advanced intermittently. Crank arm 4-6 has a -pin 41 at its distal end which is engageable in slots 31 of disc 36 to turn the latter duringffa portion ofthe-revolution of arm 46, disc 36 (and the conveyor) remaining stationary during the remainder of the revolution f arm 46. Both the pin arm 46 and gear 45 are secured to a tubular shaft 44 'which-Sis'gfeathered to an inner shaft 43 so as to be turned thereby and to provide for a limited extent'of axial'movement of the tubular shaft 44. By movingtubular shaft 44 to the right, its gear 45 meshes with gear to impart continuous movement tothe conveyor (at the same-time withdrawing pin 41 rightwardly from pin-slots l31 ofi-disc 36) ;.by'mov ing tubular shaft^44 -tothe left, gear 45 is withdrawn 'leftwardly from'meshing engagement with gear-35, and pin 1411's placed in position to-engage-the slots Y3'!v to impart intermittent movement to the conveyor. To facilitate axial shifting -of tubular shaft 144, it is provided with an annular-ly-grooved collar- 48 in which is received a pin (not shown) provided on a shift lever 338,

the lowerwend'ofiwhich 'is rpivotly mounted on a y bracketi39 secured to the machine frame.

The right end 43',Figure 4, of inner shaft 43 is coupled with-ia powershaft (not shown). Shaft "f43'n'ot`1only drives the conveyor, as just described, but also alternately raises and lowers the frotary'brushes 40,450. -fAsalready described, the '-rotarybrushes are raised and lowered by cams=49,'129, which 'raise and lower the bearing members |6, 26, `at each side -o'f the apparatus,

Figure 2. Referring -to Figure 4, cams |8,'29, are

secured to a tubular shaft59 which is feathered on an inner shaft -55 so that tubular shaft -59 may -be axially moved t-o-bringfcams |9, 29 `in. cooperative :alignment-with the --cam rollers I8, 28 ofthe bearingimembers |6, 26 which carry the rotary brushes. 'To facilitate the axial movement of tubular-shaft 159- it is provided with an annularly grooved collar 58- in which is received a `pin (not shown) provided-*cna shift leverf51, the lower end of which is pivotlymounted on a=bracket-=56 secured 1to the machine frame. VAt the right end of inner-shaft55 is -secured Va pulley or'sprocke't 54 which -is--connected by a zbelt or chain 53 to a pulley-orsprocket 49 secured at the right end 4of `powershaft43.

` The brushes 48,50, engage the surface of plastic sheet -A, 'Figure 1,=which is lmaintained in a semiplastic state by suitable heating means, such as by steam which is conducted to the lower hous- -ing 12| 'by lpipes '9. When it is desired to give vthe surface the ribbed effect or appearance as shown in Fig-ure '5, the plastic sheet is advanced in Va continuous movement through the apparatus, with ythe rotary Ibrushes 'in their lower position in cont-act with the surface of 'the semi-plastic sheet. The machine is adjusted for this operation by turning lever-38, see Fig-ure 4, to the right to mesh gear with gear v35 and fto' Withdraw pinvcrankhll 'from slotted' disc36, and by turning lever`51 to shift 'cams I9, 29 to `inoperative position. The rotary brushes 40, maybe permitted to be turned'freely by the moving .plastic sheet; in this case, manual-5, Figure 12, would fbemoved to ldisconnect spindle 81from=poWer-shaft'6,in the manner described above. 0r the rotary brushes or both of the bearings in which brush shafts 4|,

5| rotate are of split construction as shown in Figure 27 which isja det-ail ofthe split bearing 60 for brush shaft 5|. Bearing`60'is split at'one side to provide a clearance between an upper ledge 6| and a lower ledge 62 of the bearing. The lower --1edge162 fis tapped -to receive a threaded screw B3 which projects from the shank 64 of a handwheel `65,toprc`nvide an annular shoulder at the end of theshank .ilherupper ledge 6| is provided with a hole 6| through which screw 63 freely passes. Handwheel 65 is turned to advance its screw 63 upwardly, when split bearing is required to permit unrestrained rotation of shaft :5| yby turning thel handwheel inithe opposite direction, the two .ledges'6|,:'62 aresbrought closer together @to clamp the shaft :6| (and thus hold the brushes stationary relative to the advancing sheets).

.Different ribbed effects .-or `appearances will `be obtained :depending upon whether the rotary brushes are' permitted to be :freely turned by vthe advancingsheet or :are held against-such. rotation, orare positivelyldriven and,':in the 'latter case, whether they vare driven in the same direcftion as the :advancingsheetforrin'theropposite direction.

-To v'obtain the 'checkered effect shown inf Figlure-6,--the conveyor. is intermittently advanced and the brushes rotated and-alternately 'raised and lowered. 'Themanner in 4`whichilever 138, Figure 4, .is .adjusted for ,intermittent conveyor feed, and lever 51, adjusted .for alternateraising Eand lowering of the brush shafts 4|, 5|, :and the manner in which manual 5, `Figure 2, .is adjusted vfor-.rotating the-brushes, have already been described. The-raising :and lowering Acams |9, 29, see Figure 4, 'are vso timed relatively'to the intermittent conveyor drivel36, 46, that during the advance movement of the conveyor, the brushes are held lin theirsraised positions, and are lowered into contact with thefsurface of fthe plastici-sheet 'only when the conveyorl is-rstopped. It will be understoodthat'the rotary :brushes 40, 50 are in continuous rotation eso .that when :the brushes `are lowered to contact the stationary sheet, the brushes will'onake short markings-a, Figure 6, on the-surface of the sheet. The number 'of such spaced markings will.y depend upon the number of brushes on each shaft 4|, 5|. 'Since both shafts E4|, 5'| :are `mounted together in bearing members |'.6,'f26,-Figuresv1'2, two rows of short markings a will be Imade each-#time the rotary :brushes are 'lowered into contact with 'the plastic sheet. Since .the rotary fbrushesw, 50 of one shaft 4|, '51 areV staggered 'relative'to the Abrushesof-theother shaft, see Figure 2, the short markings a ofthe brushes :of therespective shafts will likewise .be staggered to :'.give'the :checkered effectshown inrFigure 6.

The surface of plastic sheets, maintainedV in asemi-'plastic state, Vmay -be given' repeated -designs vof a selected pattern, .in a'modied formiof the apparatus 'fdescribed above with reference to Figures 121. l'This is-shown in Figure 8 where the 5upper and rlowerhousings |0520 and their associated 'parts #are designated as in previous gures; -likewise'the conveyor 30 and its assoelated parts :are similarly designated, --and is shown connected (36, 4E) only for intermittent movement. The upper housing l0 is connected to the lower housing 20 in a manner to make the upper housing as air-tight as possible. Upper housing I0 is charged with compressed air conducted thereto by a pipe B. The front Wall I3, Figure 8, of upper housing I 0 is provided with an elongated slot 6B extending substantially the full length of front wall I3 and disposed just above the upper loop 3| of the conveyor. Slidably received within elongated slotl 66 is a pattern plate El which is supported, as by short ledges Within the upper housing (not shown) in a position overlying plastic sheet B carried through the housing from left to right by the conveyor. Plate 61, which may have a handle S8 (or a hand slot, not shown) to facilitate insertion and removal, is provided with small apertures 69, which represent the pattern desired to be impressed on the surface of plastic sheet B.

The compressed air being conducted, by pipe 8, into the upper housing above pattern plate 61, passes through the small pattern apertures 69 at high velocity to impinge upon the surface of the semi-plastic sheet, to cause small depressions thereon, as shown at 69X on the plastic sheet B leaving the upper housing l0, thus reproducing the design of the pattern plate. It is understood that this occurs during the stopping phase of the intermittent motion, after which the conveyor is quickly moved to present a fresh surface in underlying relation to the pattern plate. Means (not shown) may be provided to prevent passage of the compressed air through the pattern apertures of plate 61 during the advance of the plastic sheet. The conveyor is advanced the proper amount so that the design being impressed from pattern plate 61 will be contiguous to the design precedingly impressed, thus giving the plastic sheet a continuous and repeated design of the pattern. While circular apertures 69 are shown in Figure 8 for facility in illustration, the plate openings themselves may have a desired shape or outline. By interchanging the pattern plates, any desired design may thus be repeatedly reproduced.

A similar apparatus using compressed air for forming designs on the surface of plastic sheets, While in a semi-plastic state but which does not employ pattern plates (such as 61, Figure 8) is shown in Figure 9 where the housings and conveyor are designated as in Figure 8. The conveyor 30, in this case, is driven continuously to move the plastic sheet B (from left to right) in underlying relation to the nozzle ends of a plurality of compressed air tubes 10 passing through roof E i of upper housing I 0. The air being fed through tubes 10 may be heated, as by means of electric heating elements within the tubes (not shown). The jets of compressed and heated air from the nozzles of tubes 10 give the plastic sheet, maintained in semi-plastic state, the ribbed eiect shown by sheet C in Figure 9. In the form of the invention shown in Figure 9, and also in In the accompanying drawings, the invention u has been shown merely by Way of example and in preferred form, but obviously many variations and modifications may be made therein which will still be comprised within its spirit. Itis to be understood, therefore, that the invention is not limited to any specific form or embodiment, except insofar as such limitations are specified in the appended claim.

I claim:

In apparatus for treating the surface of plastic sheets, in combination, an endless conveyor, including a rotative drive member for carrying the plastic sheet, a plurality of brushes at spaced points across the width of the conveyor, a slotted disc and a gear secured for rotation with the said conveyor driven member, a power shaft, a crank arm on the said shaft having a distal pin engageable in the slots of the said disc, a gear on the said shaft meshable with the said conveyor gear, the said crank arm and gear being mounted on the said power shaft for limited axial movement selectively to a position with the said two gears meshing and the said crank arm out of engagement with the slotted disc or to a position with the said crank arm in engagement with the slotted disc and the said two gears out of mesh.

I. LAWRENCE LESAVOY.

REFERENCES CITED The following references are of record in the file of this `patent:

UNITED STATES PATENTS Number Name Date 842,356 Stone Jan. 20, 1907 1,633,216 Lakeman June 21, 1927 

